1. Field of the Invention
The present application relates generally to vibration control systems, and more specifically, to a tunable vibration system and method of same. The present application is well suited for use in the aircraft industry, in particular, helicopters, tiltrotor, and other rotor wing aircraft.
2. Description of Related Art
Vibration absorbers are well known in the art for effectively reducing, and in most cases eliminating, the vibrations of structures subject to harmonic or oscillating displacements or forces. During operation, the vibrations can cause damage to the support structures and/or other operably associated systems. The vibration absorber is configured to create a reacting force that cancels the vibrating force, and in some embodiments, the reacting force is predetermined prior to operation. It should be understood that the vibrating forces change over time or during flight conditions, for example, changing rotor RPM speeds.
In one known embodiment, a rotary system utilizes a tunable vibration absorber that creates a range of reacting forces in response to changing vibrating forces. For example, U.S. Pat. No. 5,814,963 to Girard et al. illustrates a system of the type described and is generally indicative of a current state-of-the art rotary system with a vibration absorber. In Girard et al., the conventional vibration absorber utilizes a main mass and an auxiliary mass suspended at a distance relative to the vibrating structure and coupled thereto via an elastic beam. As the vibrations change, the system is configured to adjust the auxiliary mass relative to the vibrating structure, thereby changing the reacting force. It should be understood that the motor operably associated with adjusting the auxiliary mass is not attached to the structure subject to dynamic stresses. This feature greatly reduces the life expectancy of the motor and operably associated equipment.
Although great strides have been made in the field of vibration absorbers, many shortcomings remain.
While the system and method of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the process of the present application as defined by the appended claims.